The present invention relates to a structure of arranging an FPC (flexible printed circuit) board in zoom lens barrels whose extending amounts are different.
Generally, a camera having an extendible/retractable zoom lens barrel is provided with an FPC (flexible printed circuit) board, which connects a controller in a camera body and a shutter block provided in the zoom lens. The FPC board is arranged to extend along an inner surface of the zoom lens barrel. Since there are various types of zoom lenses having different specifications, it has been difficult to use the same FPC board for different types of zoom lenses. For example, if extendible amounts of shutter blocks of two zoom lenses are different, the lengths of the FPC board should be adjusted to follow the extendible amounts, respectively. If the FPC board for a lens having a longer extendible length is used in a lens whose extendible amount is smaller, the FPC board may slack inside the zoom lens. In order to avoid the problem, it may be possible to provide an urging mechanism to apply tension to the FPC board to cancel the slack. However, such an additional mechanism requires a room therefor, and further, may raise a manufacturing cost.
It is therefore an object of the invention to provide an improved structure of arranging an FPC board in a zoom lens, with which a common FPC board can be used for various types of zoom lenses having different extendible amounts.
For the above object, according to the invention, there is provided an FPC (flexible printed circuit) board arrangement structure zoom lens barrels of a camera, the zoom lens barrels having different extendible/retractable ranges. The FPC board connects a shutter block carried by each zoom lens and a controller carried by the camera. The FPC board is configured to have a first portion to be connected to the shutter block, a second portion to be connected to the controller, and a connecting portion connecting the first portion and the second portion. The connecting portion includes at least one foldable portion and a deformable portion. The deformable portion is deformed to change its shape in accordance with a movement of the zoom lens barrel. The at least one foldable portion is folded at least when the flexible printed circuit board is implemented in one of the zoom lens barrels. It should be noted that the at least one foldable portion is unfolded when the FPC board is implemented in another zoom lens barrel.
With this structure, the same FPC board can be used for various types of zoom lenses having different extendible amounts. That is, by only folding the foldable portion depending on the extendible range of the zoom lens in which the FPC board is implemented, the length of the FPC board can easily be adjusted.
When the at least one foldable portion is folded, a first portion side area of the connecting portion may be folded. In this case, the at least one foldable portion is located, when folded, in front of the shutter block. In a particular case, the at least one foldable portion as folded may include at least one linearly extending area which extends in a direction substantially perpendicular to the optical axis.
Optionally, the at least one linearly extending area may include a plurality of linearly extending areas overlaid along the optical axis direction.
Further optionally, the at least one foldable portion may have a second foldable portion which is located at a second portion side area of the connecting portion. In an example, the second foldable portion may be folded when the flexible printed circuit board is implemented in the another zoom lens barrel. In a particular case, the second foldable portion as folded may be smoothly connected from the deformable portion to form a linearly extending portion which is substantially an extension of the deformable portion and a folded back portion overlaid on the linearly extending portion. In this case, an end of the linearly extending portion may be bent toward the controller.
In the above structure, the deformable portion may include a first area, which extends in an optical axis direction, between the shutter block and the second extendible portion, a U-shaped portion bent to form a U-shaped curved portion, and a first area, which extends in an optical axis direction, between the stationary barrel and the first extendible portion. In a particular case, a length of the deformable portion may be substantially constant regardless of an extended amount of the zoom lens barrel, the location of the U-shaped portion being changed so that a relative proportion of lengths of the first area and the second area is changed in accordance with an extended amount of the zoom lens barrel.
According to another aspect of the invention, there is provided an FPC board arrangement structure for zoom lens barrels of a camera, the zoom lens barrels having different extendible/retractable ranges. The FPC board connects a shutter block carried by each zoom lens and a controller carried by the camera. In one example, the FPC board has a first portion to be connected to the shutter block, a second portion to be connected to the controller, and a connecting portion connecting the first portion and the second portion. The connecting portion includes a plurality of foldable portions and a deformable portion. The deformable portion is a portion deformed to change its shape in accordance with the extended position of a zoom lens barrel in which the flexible printed circuit board is implemented. The plurality of foldable portions can be selectively folded in accordance with the extendible/retractable amount of the zoom lens barrel in which the flexible printed circuit board is implemented.
Optionally, the connecting portion is an elongated rectangular portion when the flexible printed circuit board is unfolded.
According to another aspect of the invention, there is provided another flexible printed circuit board arrangement structure for zoom lens barrels of a camera. The zoom lens barrels have different extendible/retractable ranges, and the flexible printed circuit board connects a shutter block carried by each zoom lens and a controller carried by the camera. The FPC board connects a shutter block carried by each zoom lens and a controller carried by the camera. The FPC board is configured to have a first portion to be connected to the shutter block, a second portion to be connected to the controller, and a connecting portion connecting the first portion and the second portion. The connecting portion includes at least one foldable portion and a deformable portion. The deformable portion is deformed to change its shape in accordance with the extended position of a zoom lens barrel in which the flexible printed circuit board is implemented. The connecting portion has at least one folded portion at least when the flexible printed circuit board is implemented in a zoom lens having a shorter extendible/retractable range, the at least one folded portion being unfolded when the flexible printed circuit board is implemented in a zoom lens having a longer extendible/retractable range.